The present invention relates to an improvement in a horizontal goods transfer apparatus for mounting goods on its elongated rail and intermittently transferring the goods.
As is known well, an example of the horizontal goods transfer apparatus of this type includes a conveyor that merely transfers goods and a flow-through rack that performs both transfer and storage of goods. Regarding the flow-through rack of these two examples, one shown in Jpn. UM Appln. KOKOKU Publication No. 2-31449 is filed by the present applicant as a prior art.
The flow-through rack indicated in this publication has fixed rails, vertical movement rails installed along the fixed rails to move upward/downward upon inflation/deflation of a flexible tube, and back-and-forth movement rails supported by the vertical movement rails to be movable back and forth with a predetermined stroke to move upward/downward together with the vertical movement rails.
An item of goods is placed on the fixed rails, and the flexible tube is inflated to move the vertical movement rails upward. The goods item placed on the fixed rails is lifted by the back-and-forth movement rails moved upward together with the vertical movement rails, so that it floats from the fixed rails.
Thereafter, the back-and-forth movement rails mounting the goods item thereon are moved forward by an amount corresponding to their stroke, thereby moving the vertical movement rails downward. Then, the back-and-forth movement rails are moved downward together with the vertical movement rails. The goods item is transferred from the back-and-forth movement rails to the fixed rails. As a result, the goods item is moved forward by an amount corresponding to the stroke of the back-and-forth movement rails.
The back-and-forth movement rails are moved backward to the original position, and the above operation is repeated, so that items of goods are intermittently transferred along the fixed rails.
In the conventional horizontal goods transfer apparatus having the above arrangement, however, since the flexible tube must move not only the vertical movement rails but also the back-and-forth movement rails together with the goods, the flexible tube must have a structure and a material capable of enduring a considerably large weight.
If a reciprocally driving means for driving the back-and-forth movement rails is also mounted on the vertical movement rails, the load that must be moved upward/downward by the flexible tube further increases. Members and structures capable of upholding higher pressures are required, leading to an economical disadvantage.